1. Field of the Invention
The present invention relates to a seek control system in a disk device, e.g., a magnetic disk device. More specifically, the present invention relates to a technique for controlling a disk device during seek operations, as an overheating countermeasure of a disk device, which is used to counter overheating of a voice coil motor (usually abbreviated to "VCM") in a magnetic disk device, etc.
2. Description of the Related Art
In recent years, demands for magnetic disk devices with high processing speed (e.g., high access speed) have resulted in the drive of a large current through the VCM during seek operations in order to obtain the maximum possible performance. For this reason, the problem occurs that, when seek operations are performed continuously, with a large current supplied to the VCM, the VCM may be damaged by overheating. A solution to this problem is required.
Here, to enable the configuration of a conventional seek control system in a disk device to be understood more clearly, the related art and the disadvantages therein will be described with reference to the related drawings of FIG. 1 through FIG. 3.
FIG. 1 is a block diagram showing a configuration of a conventional magnetic disk device; FIG. 2 is a block diagram for explaining a technique for detecting the temperature of a VCM according to the prior art; and FIG. 3 is a diagram showing a VCM current and a temperature waveform related to the prior art.
In FIG. 1 through FIG. 3, 1 denotes a magnetic disk device (magnetic disk drive); 2 denotes a disk enclosure (sometimes abbreviated to "DE"); 3 denotes a spindle motor; 4 denotes a spindle; 5 denotes a plurality of magnetic disks, 6 denotes a voice coil motor (usually abbreviated to "VCM"); 7 denotes the magnetic heads; and 9 denotes a control section.